sumatriptan, Imitrex
Relationship between chronic tension-type headache, cranial hemodynamics, and cerebrospinal pressure: study involving provocation with sumatriptan.

Hannerz J, Jogestrand T.

Department of Neurology, Karolinska Hospital, Huddinge University Hospital, Stockholm, Sweden.

OBJECTIVE: To study the relationship between chronic tension-type headache, cranial hemodynamics, and cerebrospinal pressure. BACKGROUND: Cerebrospinal pressure has been found to be above 200 mm in about 50% of patients with chronic tension-type headache. METHODS: Heart rate, blood pressure, common carotid artery diameter and blood flow, and craniovascular resistance and pain at regular intervals before, during, and after head-down tilt-a procedure which increases cerebrospinal pressure, were recorded. After head-down tilt, subcutaneous injections of either placebo or 6 mg of sumatriptan were administered. Chronic tension-type headache intensity before and after withdrawal of 20 mL of cerebrospinal fluid was documented. Cerebrospinal pressure and chronic tension-type headache intensity were measured after subcutaneous injection of 6 mg of sumatriptan. RESULTS: Head-down tilt provoked an increase of headache compared with baseline. Common carotid artery blood flow decreased and craniovascular resistance increased after sumatriptan injection, but not after placebo injection. The pain decreased after head-down tilt and placebo injection, but not after sumatriptan injection. Chronic tension-type headache intensity decreased in all 4 patients studied after withdrawal of 20 mL of cerebrospinal fluid. Cerebrospinal pressure increased in 5 patients with chronic tension-type headache after subcutaneous injection of 6 mg of sumatriptan with slight or no increase of pain. CONCLUSION: The results indicated that cerebrospinal pressure or intracranial venous pressure (or both) are related to chronic tension-type headache.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14756854&dopt=Abstract sumatriptan Imitrex



sumatriptan, Imitrex
Disruption of communication between peripheral and central trigeminovascular neurons mediates the antimigraine action of 5HT 1B/1D receptor agonists.

Levy D, Jakubowski M, Burstein R.

Departments of Anesthesia and Critical Care, Beth Israel Deaconess Medical Center, Boston, MA 02115, USA.

Triptans are 5HT(1B/1D) receptor agonists commonly prescribed for migraine headache. Although originally designed to constrict dilated intracranial blood vessels, the mechanism and site of action by which triptans abort the migraine pain remain unknown. We showed recently that sensitization of peripheral and central trigeminovascular neurons plays an important role in the pathophysiology of migraine pain. Here we examined whether the drug sumatriptan can prevent and/or suppress peripheral and central sensitization by using single-unit recording in our animal model of intracranial pain. We found that sumatriptan effectively prevented the induction of sensitization (i.e., increased spontaneous firing; increased neuronal sensitivity to intracranial mechanical stimuli) in central trigeminovascular neurons (recorded in the dorsal horn), but not in peripheral trigeminovascular neurons (recorded in the trigeminal ganglion). After sensitization was established in both types of neuron, sumatriptan effectively normalized intracranial mechanical sensitivity of central neurons, but failed to reverse such hypersensitivity in peripheral neurons. In both the peripheral and central neurons, the drug failed to attenuate the increased spontaneous activity established during sensitization. These results suggest that neither peripheral nor central trigeminovascular neurons are directly inhibited by sumatriptan. Rather, triptan action appears to be exerted through presynaptic 5HT(1B/1D) receptors in the dorsal horn to block synaptic transmission between axon terminals of the peripheral trigeminovascular neurons and cell bodies of their central counterparts. We therefore suggest that the analgesic action of triptan can be attained specifically in the absence, but not in the presence, of central sensitization.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15016917&dopt=Abstract sumatriptan Imitrex



sumatriptan, Imitrex
Inter-digestive and post-prandial antro-pyloro-duodenal motor activity in humans: effect of 5-hydroxytryptamine 1 receptor agonism.

Calvert EL, Whorwell PJ, Houghton LA.

Academic Department of Medicine, University Hospital of South Manchester, Manchester, UK.

BACKGROUND: Little is known about the effect of 5-hydroxytryptamine 1 (5-HT(1)) receptor agonism on the co-ordinated motor activity of the gastric antrum, pylorus and duodenum under fasting and fed conditions. AIM: To evaluate the effect of sumatriptan, a 5-HT(1) agonist, on fasting and fed antro-pyloro-duodenal motility. METHODS: In study 1, antro-pyloro-duodenal motility was recorded for two phase IIIs of the migrating motor complex and then, following either a subcutaneous injection of sumatriptan 6 mg or saline control, for at least one additional phase III in 11 healthy volunteers (21-36 years). In study 2, the post-prandial motility was recorded for 3 h after either a subcutaneous injection of sumatriptan 6 mg or saline control in 10 healthy volunteers (18-36 years). RESULTS: Sumatriptan prolonged the migrating motor complex cycle (P = 0.009) by increasing the duration of phase II (P = 0.02) but not phases I and III. Post-prandially, sumatriptan reduced the activity index (P = 0.017) by reducing the frequency of co-ordinated motor activity involving the antrum and/or the duodenum (P < 0.05). CONCLUSION: 5-HT(1) receptor agonism increases the periodicity of the migrating motor complex and reduces the occurrence of post-prandial co-ordinated motor activity involving the gastric antrum, pylorus and duodenum.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15043522&dopt=Abstract sumatriptan Imitrex



sumatriptan, Imitrex
Effects of chronic sumatriptan and zolmitriptan treatment on 5-HT receptor expression and function in rats.

Reuter U, Salomone S, Ickenstein GW, Waeber C.

Stroke and Neurovascular Regulation Laboratory, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA. uwe.reuter charite.de

Triptans are commonly used anti-migraine drugs and show agonist action mainly at serotonin 5-HT(1B/1D/1F) receptors. It is not known whether frequent or long-term treatment with these drugs would alter 5-HT receptor function. We investigated the effects of protracted (14-18 days) sumatriptan and zolmitriptan treatment in rats on 5-HT(1) receptor mRNA expression and function in tissues related to migraine pathophysiology. RT-PCR analysis revealed that 5-HT(1B/1D/1F) receptor mRNA was reduced in the trigeminal ganglion after treatment with either triptan (reduction by: sumatriptan 39% and zolmitriptan 61% for 5-HT(1B); 60%vs 41% for 5-HT(1D); 32%vs 68% for 5-HT(1F)). Sumatriptan attenuated 5-HT(1D) receptor mRNA by 49% in the basilar artery, whereas zolmitriptan reduced 5-HT(1B) mRNA in this tissue by 70%. No change in 5-HT(1) receptor mRNA expression was observed in coronary artery and dura mater. Chronic triptan treatment had no effect in two functional assays [sumatriptan mediated inhibition (50 mg/kg, i.p.) of electrically induced plasma protein extravasation in dura mater and 5-nonyloxytryptamine-stimulated [(35)S]guanosine-5'-O-(3-thio)triphosphate binding in substantia nigra]. Furthermore, vasoconstriction to 5-HT in isolated basilar artery was not affected by chronic triptan treatment, while it was slightly reduced in coronary artery. We conclude that, although our treatment protocol altered mRNA receptor expression in several tissues relevant to migraine pathophysiology, it did not attenuate 5-HT(1) receptor-dependent functions in rats.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15096229&dopt=Abstract sumatriptan Imitrex



sumatriptan, Imitrex
Quantifying delay in access to new medical treatment: an application of risk advancement period methodology.

Krobot KJ, Miller WC, Kaufman JS, Christensen DB, Preisser JS, Ibrahim MA.

Department of Epidemiology, School of Public Health, The University of North Carolina at Chapel Hill, North Carolina, USA. kkrobot web.de

BACKGROUND: We present a novel application of the concept of risk or rate advancement to compute the extent of delay in adoption of an effective new drug in 2 German health insurance systems. METHODS: We identified individuals with migraines, age 18 to 65 years, in 371 primary care practices in Germany in 1994 (MediPlus, IMS Health database). These included 8173 persons covered under the statutory health insurance system and 503 persons covered by private health insurance. We derived risk and population risk advancement periods for sumatriptan compared with nonserotoninergic acute migraine therapy using multiplicative risk regression and generalized estimating equations, adjusted for patient, physician, and practice cofactors. RESULTS: For patients at the mean age of the cohort, 43 years of age, sumatriptan was prescribed 1.2 (95% confidence interval [CI] = 0.3-2.0) years later among those in the statutory health insurance system compared with those who had private insurance. The lag increased by 0.6 (-0.1 to 1.3) years for every 10 years of patient age. In the age-mix of our sample, access to the health benefits of sumatriptan therapy lagged nearly 1.5 years behind in the statutory health insurance system and for Germany as a whole. CONCLUSIONS: Migraine patients' access to sumatriptan therapy lagged substantially in the statutory health insurance system and in the country as a whole. Risk advancement periods provide a useful methodology for communicating major healthcare issues in a meaningful way to society and policymakers.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15127913&dopt=Abstract sumatriptan Imitrex



sumatriptan, Imitrex
High performance liquid chromatographic method for the determination of sumatriptan with fluorescence detection in human plasma.

Ge Z, Tessier E, Neirinck L, Zhu Z.

Pharmascience, 6111 Royalmoount Avenue, Suite 100, Montreal, Que., Canada H4P 2T4.

A rapid and sensitive high performance liquid chromatography (HPLC) method with fluorescence detection has been developed for the determination of sumatriptan in human plasma. The procedure involved a liquid-liquid extraction of sumatriptan and terazosin (internal standard) from human plasma with ethyl acetate. Chromatography was performed by isocratic reverse phase separation on a C18 column. Fluorescence detection was achieved with an excitation wavelength of 225 nm and an emission wavelength of 350 nm. The standard curve was linear over a working range of 1-100 ng/ml and gave an average correlation coefficient of 0.9997 during validation. The limit of quantitation (LOQ) of this method was 1 ng/ml. The absolute recovery was 92.6% for sumatriptan and 95.6% for the internal standard. The inter-day and intra-day precision and accuracy were between 0.8-3.3 and 1.1-6.3%, respectively. This method is simple, sensitive and suitable for pharmacokinetics or bioequivalence studies.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15171943&dopt=Abstract sumatriptan Imitrex



sumatriptan, Imitrex
Influence of 5-HT1 receptor agonists on feline stomach relaxation.

Janssen P, Tack J, Sifrim D, Meulemans AL, Lefebvre RA.

Center for Gastroenterological Research, University of Leuven, Leuven, Belgium. Janssen_Pieter hotmail.com

Sumatriptan is known for its stomach relaxing properties in both humans and cats, but the receptor involved has not been characterized. In a barostat study the intragastric volume was monitored in sedated cats at constant pressure. The maximum intragastric volume increase after subcutaneous or intravenous administration of saline or agonists was registered [mean (n=4-5)]. Sumatriptan (0.01-1 mg kg(-1)) induced a dose-dependent intragastric volume increase vs. saline (4-15 vs. 5 ml, respectively) that was sometimes accompanied by retching after 8-10 min. Pre-treatment with nitric oxide-synthase inhibitors and different 5-HT(1) receptor antagonists N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-2-pyridinyl-cyclohexanecarboxamide(WAY-100635), 2-methyl-4-(5-methyl-[1,2,4]oxadiazol-3-yl)-biphenyl-4-carboxylic-acid[4-methoxy-3-(4-methyl-piperazin-1-yl)-phenyl]amide(GR-127935), N-acetyl-5-hydroxytryptophyl-5-hydroxytryptophan-amide(5-HTP-DP) and 1-(2-methoxyphenyl)-4-[4-(2-phthalimido)butyl]piperazine-HCl(NAN-190) did not affect the sumatriptan-induced effect. Alniditan (5-HT(1A/1D) receptor agonist) and flesinoxan (5-HT(1A) receptor agonist) did not induce significant intragastric volume changes. The 5-HT(1F) receptor agonists 5-hydroxy-3-(1-methylpiperidin-4-yl)-1H-indole(BRL-54443) and (R)-(+)-N-(3-dimethylamino-1,2,3,4-tetrahydro-9H-carbazol-6-yl)-4-fluorobenzamide(LY-344864; 0.003-3 mg kg(-1)) however induced a dose-dependent intragastric volume increase (6-36 and 5-26 ml, respectively), no retching was seen. Our results suggest that stimulation of 5-HT(1F) receptors induces feline stomach relaxation. Whether the sumatriptan-induced gastric relaxation in cats is due to interaction with 5-HT(1F) receptors could not be proven absolutely in view of the lack of selective 5-HT(1F) receptor antagonists.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15178373&dopt=Abstract sumatriptan Imitrex